Liquid for transferring energy and lubricating



efficient lubricants.

Patented Dec. 18, 1934 LIQUID FOR TRANSFERRING ENERGY AND LUBRICATINGYEduard Muench-and Hanns Ufer, Ludwigshafenon-the-Rhine, Germany,assignors to I. G. Farbenindustrie Aktiengesellschaft,Frankfort-onthe-Main, Germany No Drawing.

Application November 13,1930,

Serial No. 495,415. In Germany November 23;

6 Claims.

The present invention relates to liquids for transferring energy andlubricating.

It is well known that castor oil and other vegetal, i. 8. animal ormineral, oils and fats are If however such lubricants are used inhydraulic machinery, such asfiuid brakes, as means for transferringenergy a disadvantage occurs which consists in the considerable increaseof viscosity of the saidmaterials at low temperatures. It has beenalready suggested to diminish the viscosity by adding ethyl alcohol tocastor oil but these mixtures corrode metals. In order to obviate thisdeleterious effect alkali metal hydroxide or alkali metal salts, inparticular arsenites or phosphates, have been added but withinsufiicient results and the substitution of butyl alcohol for ethylalcohol has not proved satisfactory as regards corrosion.

We have now found that liquids for transferring energy and lubricatingcan be prepared by mixing liquid ethers, especially ethers of theglycols or polyglycols, or mixtures thereof, with oily lubri eatingagents such as vegetable, animal or min-- eral oils, especially. withcastor 'oil, and if desired with further ad .litions of diluents,alkaline agents or agents retarding oxidation or,several of such agents.The components of the said mixtures must of course be so chosen thatthey are miscible with each other at the temperatures concerned in theapplication of the mixtures for the said purposes. The ratio between theethers and oily lubricating agents'varies in rather wide limitsdepending on the purpose intended for the preparations; thus thequantity of ether may be from 5 to 200 per cent of the oily lubricatingagents, provided these quantities dissolve in each other, which is thecase with most ethers and especially with vegctal, i. e. vegetable andanimal oils. Certain mineral lubricating oils such as those ofPennsylvanian origin are less compatible in many cases with ethers oflow molecular weight in which the ratio of oxygen to carbon is ratherhigh, and in these cases quantities of ether of from about 5 to about 30per cent are preferred. The ethers employed may be chosen from anyethers containing aliphatic radicles and we wish the term ethers to beunderstood as not including purely aromatic compounds such as diphenyloxide and the like. The ethers can be chosen from all those ethers whichhave a melting point below zero centigrade and are therefore liquidunder normal conditions. Suitable ethers are the symmetrical andunsymmetrical aliphatic ethers as for example methyl, ethyl, propyl,butyl, heptyl and decyl ethers, methyl grade) Viscosity (in degreesEngler) l dodecyl ether, dibenzyl ether, the alkyl and aryl ethers ofglycols, of polyglycols and of other higher polyhydric alcohols andsimilar ethers provided they fulfil the requirements as regards theirmelting point. The low aliphatic ethers such as di-methyl ether, methylethyl ether or di-ethyl ether.may be employed for use at lowtemperatures but should not be employed in preparations for use attemperatures above the boiling pointof the said ethers. I

Since by the addition of the ethers, the setting point of the oilscontained in the mixture is lowcred with the simultaneous reduction ofthe viscosity of these oils at the temperatures concerned, such mixtureshave a viscosity especially suitable for the aforesaid purpose and maybe accommo-. dated to the requirements by appropriate choice of theproportions or components of the mixture in a manner in which no othermixtures can. This is especially important because,in the apparatus andmachines necessary for the various purposes, the openings for the flowof the pressure transferring liquids, as for example nozzles, valvesTemperature (in degrees centigrade.. Viscosity (in degrees Engler) Withethylene glycol mono butyl ether the corresponding viscosities are:

Temperature (in degrees centi- 0 13 gra Viscosity (in degrees Engler) 49A mixture of 1 part of castor oil with 2 parts of polyethylene-glycolmono-ethyl ether has the a following viscosities;

Temperature (in degrees centi- A mixture of 2 parts of castor oil and 1part of commercial poly-ethylene glycol mono-butyl ether has a viscosityof about 45 Engler at 50 C.

On an average the alteration in the viscosity with the temperature isthus much smaller than with oils, as can be seen from the followingtable in which the ratio of the times of outflow from a capillary glasspipe are given:

Ratio of times of outflow at- Mixture in parts by weight 50 C. 0. 0 C.20 C.

l palit ogtcaistor olil anld 2 pagtstoi o e ene co mono u the nu jnnfiz.3 1 2. 4 5. 7 21 1 D3111; 0g l1calstor olil allid 2 parts1 oi 0 ye eneco mono-ct y Ether. Z l 2. 4 5. l 20 l 1 part of castor oil and 2 partsof ethylene glycol mono-butyl ether 1 2.0 4. 2 13 1 part of castor oiland 2 parts of ethylene glycol monoethyl ether l 1.7 2.8 6.9

The values given vary somewhat by reason of slight differences in theinitial materials. lBy employing other mixtures especially those ofmixtures of the mixtures specified with other ethers of ethylene glycolor of polyethyleneglycol, as for example etlwleneglycol' mono-cresylether, ethylene glycol diethyl ether, and the like, the viscosities atthe different temperatures may be still more adapted to the purpose inview.

In the place of, or together with, the ethers of glycols or ofpolyglycols other ethers may be employed, for example symmetrical ormixed ethers of monohydric aliphatic, cycloaliphatic or aliphaticaromatic alcohols, provided that. the

ethers possess a boiling point above the temperature which may arise inthe particular application desired. Thus, for example a mixture of equalpart by Weight of castor oil and of din-butyl ether has the followingviscosities: at 20 C. 7.9 Engler, at 0 0. 3.4. Engler, at 20 C. 1.9Engler and at 50 C. 1.4 Engler, whereas a similar mixture with ethylalcohol in the place of the ether has a viscosity at 20 of Engler. Amixture of 2 parts of mineral oil, 1 part of icemachine oil and 1 partof di-butyl ether shows the following viscosity values at the aforesaidtemperatures: 3.1, 1.7, 1.3 and 1.1. The viscosity of Gargoyle MobileOil BB which corresponds to a period for effluing from the Englerviscos-- imeter at 20 C. of 406 seconds is reduced to 235 seconds by anaddition of 5 per cent of dibenzyl ether and to 82 seconds by anaddition of 10 per cent of di-butyl ether. Of the oils, castor oil hasbeen found to be especially suitable by reason of its good lubricatingpower and its small attack .on caulking materials especially on rubber.A great variety of kinds of castor oil may be employed, including thosewhich have been rendered miscible with mineral oils, and also mixturesof these oils with other oils, such as mineral oils or vegetable oilsother than castor oil. For example a mixture of -parts by volume of acastor oil miscible with mineraloil, 30 parts byvolume of ethyleneglycol mono-cresyl ether and,

10 parts by volume of mineral oil, which remains completely clear at 10below zero centigrade may be mentioned. Moreover, mixtures of 20 Partsof an oil having a low setting point such as the oils known in the tradefor lubricating ice-machines and 20 parts of poly-ethylene glycolmono-butyl ether, or of 20 parts of a mineral lubricating oil and from20to parts of ethylene glycol mono-butyl ether are very useful, andlikewise mixtures of 10 parts of mineral lubricating oil, 10 parts ofice-machine oil and from 4 to 10 parts of ethylene glycol mono-butylether or of di-n-butyl ether.

. In order to prevent any corrosion of metals such as iron, steel,copper and the like, by a content of free acids in the oils it ispreferable to employ neutral oils, such as are obtained for example byheating the acid =oils with ethylene oxide or a homologue thereof or toadd to the mixtures small amounts of basic compounds such as alkalimetal hydroxides, alkaline reacting salts of the oxygen acids ofphosphorus, carbonates and the like, which, if necessary, may bepreviously dissolved in suitable solvents, as for example ethyl alcohol,in order to produce clear mixtures.

When employing commercial ethers, it is frequently preferable to purifythem for this purpose by a treatment with alkalies and subsequentdistillation. With oils which undergo change by the oxygen of the airsuch as vegetable or animal oils it is sometimes preferable to addagents for preventing oxidation as for example those used in the rubberindustry such as aldol-alpha-naphthylamine, or other agents such as ureaand the like.

The said mixtures may be used as powertransferring and lubricatingliquids for a great variety of hydraulic apparatus and machines, as forexample for brakes, shock-absorbers, presses, lifting apparatus and thelike.

What we claim is:--

1. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of a liquid polyglycol ether and a lubricating oil.

2. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of a liquid glycol ether, a liquid polyglycol ether and alubricating oil.

3. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of a liquid polyglycol ether and a vegetable lubricating oil.

4. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of a liquid polyglycol ether and castor oil.

5. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of about equal parts by weight of neutral castor oil and ofpolyethylene glycol mono-ethyl ether.

6. As a composition of matter suitable for transferring energy andlubricating, a practically anhydrous, limpid, homogeneous mixtureconsisting of a liquid polyglycol ether and a mineral lubricating oil. v

EDUARD MUENCH. HANNS UFER.

